Ernest Borisovich Vinberg (Russian: Эрнест Борисович Винберг; 26 July 1937 – 12 May 2020) was a Russian mathematician, who worked on discrete subgroups of Lie groups and representation theory. He introduced Vinberg's algorithm and the Koecher–Vinberg theorem. He was a recipient of the Humboldt Prize. He was on the executive committee of the Moscow Mathematical Society. In 1983 he was an Invited Speaker with a talk on Discrete reflection groups in Lobachevsky spaces at the International Congress of Mathematicians in Warsaw. In 2010 he was elected a member of the American Academy of Arts and Sciences...